The JBL MTC-81BB8 backcan is purpose-built for integrators installing the 8138 ceiling speaker in new construction and retrofit applications. Its generous 7.4-liter internal volume creates an acoustic chamber that extends low-frequency performance beyond what surface-mount or smaller enclosures can deliver, making it ideal for ballrooms, hospitality venues, and large open spaces where full-range coverage is required.

Constructed from 16-gauge steel with durable powdercoating, the backcan features five conduit knockouts positioned on the can body and top panel for flexible wire routing during rough-in. The industry-standard 286mm bolt-mounting circle integrates directly with the 8138 speaker frame, while dual suspension tabs support secure ceiling joists or framing. Nesting design during storage reduces footprint for integrators managing multiple installations, and the unit ships in packs of four for multi-room projects.